In the Sanabria World Airmail catalog, 1966 edition, it is stated that the stamp was issued October 15, 1938, "used on the first official experimental postal rocket flight in the world, held at Havana under the auspices of the Philatelic Club of Cuba and the Department of Communications."
It is also noted that 200,000 were issued, and the catalog valuation at that time was indicated as $40.00 unused, $10.00 used, and $75.00 on cover.
Here you can find more information about this interesting stamp. All information is from Edifil catalogue 2012 Edition, it is a spanish catalogue for Cuba stamps.
Please, check it all variety for postal history studies.